. >> this is possibly the greatest which has occurred, certainly, in the united states, that i'm aware of. >> reporter: so far, eight people have come down with the hantavirus. three of them have died in states as far flung as california, pennsylvania and west virginia. and there could be more cases as far away as france. the main outbreak traced to the popular curry village campsite, where rhodens burroed into tents. now, a second site. warnings like these went out to 10,000 people who visited curry village since june. late this week, notices went out to an additional 19 visitors at tuolome visitors. 29,000 park visitors in all, all being warned about the hantavirus symptoms. they include fever, fatigue, and chills at first. they give way to coughing, breathing problems as the lungs filled with fluid. >> i had a mouse run across my head. scared me pretty good. >> the only way for someone to contract hantavirus, is to breathe in particles of mouse feces and fluid. >> reporter: it's easy to think the initial symptoms are a common flu. while there's no cure, early detection, as well as s